The invention relates to a lowering mechanism for a foil roll in a device for winding up a foil web, particularly a a foil web of synthetic material. According to the invention the foil web is guided between a contact roller and the foil roll fitted with a roll core. The roll core carrying the finished foil roll can be received at its end by lowering arms and deposited on a discharge level by means of a lowering-arm drive. The lowering arms can be raised again with the aid of a lowering-arm drive. This invention relates particularly--but is not limited--to such a device wherein a horizontally running support guide rail is provided, whereupon the ends of the roll core are supported.
In known devices of this kind the lowering arms are equipped with lever arms with cylinder-piston arrangements engaging therewith, thus controlling the lowering motion. They are mostly set in motion via limit switches, which are activated by the roll cores with the wound-up foil roll when these reach the position for lowering. In an arrangement of this type, it has to be accepted that the torque which has to be applied or supported by the cylinder piston arrangement changes with the lowering angle. On the other hand, a relatively high torque which depends on the diameter of the foil roll and under certain circumstances results from tons of weight, has to be absorbed. As a result, the known steps are expensive, particularly from the point of view of driving and control techniques.
It is the object of the invention to simplify, from the point of view of driving and control techniques, the lowering operation of a roll core bearing the finished foil roll in a generic device.